Harry Potter" author J.K. Rowling is to write her first novel for adults, her new publishers announced Thursday.Joel Ryan/AP

LONDON — “Harry Potter” author J.K. Rowling is to write her first novel for adults, her new publishers announced Thursday.

“The rumors are true … We’re going to publish J.K. Rowling’s First Novel For Adults! We’re so excited!” US publishing house Little, Brown and Company said on Twitter.

It is not yet known what the book will be about or what it will be called but further details will be released later this year, the company said.

“Although I’ve enjoyed writing it every bit as much, my next book will be very different to the Harry Potter series,” Rowling said in a statement.

“The freedom to explore new territory is a gift that Harry’s success has brought me,” she added.

Little, Brown and Company will publish the book in the US, while Little, Brown Book Group will publish it in the UK. Rowling’s successful “Harry Potter” series of books were published by Scholastic in the US and Bloomsbury in the UK.

The bestselling author said she had chosen new publishers to mark “this new phase of my writing life.”